A high-order spiral combination twisted-lobe Roots rotor, compressor and expander

Abstract

A high-order spiral combined twisted lobe Roots rotor, compressor and expander. The rotor includes a female rotor and a male rotor with the same profile structure. The two rotors can achieve continuous and correct meshing during the meshing process of reverse rotation. The tooth profile A1B1C1D1E1 of a single tooth of one rotor is composed of a spiral envelope line segment A1B1, a spiral line segment B1C1, a spiral line segment C1D1 and a spiral envelope line segment D1E1 connected in sequence. The complete rotor profile is formed by rotating the single-tooth profile A1B1C1D1E1 around the origin of its rotor profile by #imgabs0# and then connecting the head and tail with the single-tooth profile A1B1C1D1E1. z represents the number of teeth of different rotor profiles. The rotor profile of the present invention has five adjustable profile parameters, including the spiral order, the number of rotor teeth, the rotor center distance and two profile geometric parameters, and has a greater optimization space in terms of profile design and adaptability; according to the needs of the design working conditions, the shape of the rotor profile can be flexibly adjusted to improve the volumetric efficiency, energy-saving performance and dynamic characteristics.

Description

Technical Field

[0001] The invention belongs to the field of rotary machinery design and processing, and particularly relates to a high-order spiral combined twisted-lobe Roots rotor, a compressor and an expander. Background Art

[0002] The twisted-lobe Roots compressor and expander are a kind of widely used rotary compressors and expanders, which can be used to obtain the transportation and compression of fluid working medium under medium and low pressure conditions. It has the characteristics of long service life of rotary machinery, continuous and reliable operation, low vibration and noise, and stable operation. At the same time, it also has the characteristics of no valve structure, forced suction and exhaust, simple processing, and few wearing parts, and plays an important role in machinery such as air compressors in fuel cell systems and semiconductor vacuum pumps.

[0003] The twisted-lobe Roots compressor and expander rely on the pushing action of a pair of rotor blades with the same shape in the rotor cavity rotating synchronously and in opposite directions to realize gas transportation. Its rotor determines the overall performance of the compressor and expander. The optimal design of the rotor is also the key technology for manufacturing high-performance twisted-lobe Roots compressors and expanders. However, the current widely used profiles of twisted-lobe Roots compressors and expanders have few design optimization parameters in terms of tooth profile serialization. In order to meet different requirements, it is necessary to redesign and optimize the profile parameters. Summary of the Invention

[0004] The purpose of the invention is to provide a high-order spiral combined twisted-lobe Roots rotor, a compressor and an expander for the problem of insufficient design optimization parameters of the rotor tooth profile serialization of the existing twisted-lobe Roots compressors and expanders. Through the reasonable combination of different-order spiral profiles, a complete twisted-lobe Roots rotor tooth profile is formed, which can meet the requirements of profile serialization while providing more design parameters, so as to effectively suppress the leakage between working cavities under different operating conditions, improve the rotor area utilization coefficient, and improve the overall performance of the twisted-lobe Roots compressor and expander.

[0005] In order to achieve the above purpose, the invention has the following technical solutions:

[0006] A high-order spiral combined twisted-lobe Roots rotor includes a female rotor and a male rotor with the same profile structure. The two rotors can achieve continuous and correct meshing during the meshing process of reverse rotation. The single-tooth tooth profile A1B1C1D1E1 of one rotor is composed of a spiral envelope line segment A1B1, a spiral line segment B1C1, a spiral line segment C1D1, and a spiral envelope line segment D1E1 connected in sequence. The complete rotor profile is formed by rotating the single-tooth tooth profile A1B1C1D1E1 around the origin of its rotor profile Then it is formed by connecting the single-tooth profile A1B1C1D1E1 end to end. Repeat this rotation and connection z times, where z represents the number of teeth of different rotor profiles; during the rotation, the origin of the rotor profile of one rotor is O1, and the origin of the rotor profile of the other rotor is O2; the involute envelope segment A1B1 of one rotor (the male or female rotor) meshes with the involute segment A2B2 of the other rotor, the involute segment B1C1 meshes with the involute envelope segment B2C2 of the other rotor, the involute C1D1 meshes with the involute envelope segment C2D2 of the other rotor, and the involute envelope D1E1 meshes with the involute D2E2 of the other rotor.

[0007] In a preferred embodiment, the single-tooth profile A1B1C1D1E1 is considered to be composed of two profile segments A1C1 and C1E1. The two profile segments A1C1 and C1E1 are respectively composed of different or the same involute and its envelope. A combined profile segment composed of an involute and its envelope is an involute tooth profile.

[0008] The involute profile equation is as follows:

[0009]

[0010] In the formula, n i represents the specific order of the involute profile, and a and b are adjustable geometric parameters of the profile;

[0011] Derived according to the plane meshing principle, the central angle of the rotor corresponding to each involute tooth profile satisfies the following relationship:

[0012]

[0013] Two involute tooth profiles with different orders that satisfy this relationship form a single-tooth profile.

[0014] In a preferred embodiment, a complete rotor tooth profile is composed of different rotor single-tooth profiles. The specific profile matrix is as follows:

[0015]

[0016] In the formula, P i,a and P i,b respectively represent the profile parameter matrices of each involute tooth profile of the two meshing rotors, and P a and P b respectively represent the total profile parameter matrices of the two meshing rotors. The subscripts a and b represent the two rotors respectively, and i represents each involute tooth profile.

[0017] In a preferred embodiment, the profile obtained by combining involute tooth profiles of different orders satisfies the following relationship:

[0018] P i,[a,b] (end) = P i+1,[a,b] (first)

[0019] P i,[a,b] (end)' = P i+1,[a,b] (first)'

[0020] Wherein, P i,[a,b] 、P i,[a,b] ' respectively represent the profile parameter matrix and the profile derivative parameter matrix of any section of the spiral tooth profile on two rotors, and end and first represent two points where the profiles are connected end to end.

[0021] In a preferred embodiment, the number of teeth z of different rotor profiles satisfies the following relationship:

[0022]

[0023] Thus, the rotor spiral tooth profile orders n with different numbers of teeth z have the following profile configuration schemes:

[0024]

[0025] Wherein,

[0026] A twisted lobe Roots compressor having the high-order spiral combined twisted lobe Roots rotor as described above.

[0027] A twisted lobe Roots expander having the high-order spiral combined twisted lobe Roots rotor as described above.

[0028] A design method for the high-order spiral combined twisted lobe Roots rotor as described above, comprising the following steps:

[0029] Select the rotor center distance O1O2, the number of teeth z of different rotor profiles, and the adjustable geometric parameters a and b according to the volume size and pumping rate;

[0030] Arrange and combine to select the orders n of the spiral line segments B1C1 and C1D1 i , and construct the rotor profile through the selected parameters;

[0031] The profile tooth profiles combined by different-order spirals have different meshing lines and force characteristics. In the actual application process, optimize and select different arranged-profile rotors according to the sealing requirements and force performance requirements of the specific use scenario.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] The profile structures of the male rotor and the female rotor have five adjustable parameters, including the order of the spiral curve, the number of teeth, the center distance between the rotors, and the profile geometric parameters of the two rotors, providing a greater optimization space in terms of profile design and adaptability. The profile of the high-order spiral curve combined twisted-lobe Roots rotor of the present invention can form a series of rotor spiral curve tooth profiles by selecting the order of the spiral curve according to the number of rotor teeth and design requirements. According to the needs of the design working conditions, the shape of the rotor profile can be flexibly adjusted, so that the volumetric efficiency, energy-saving performance, and dynamic characteristics of the optimized twisted-lobe Roots rotary machinery are improved. Compared with other conventional pump types, the compressor and expander using the high-order spiral curve combined twisted-lobe Roots rotor of the present invention have the advantages of fewer wearing parts, forced suction and exhaust, high pumping speed, no surging, low vibration and noise, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the profile of the high-order spiral curve combined twisted-lobe Roots rotor in the embodiment of the present invention:

[0035] z a = z b = 3, n = [2, 6, 2, 6, 3, 3].

[0036] Figure 2 Schematic diagram of the envelope line cluster of the profile of the high-order spiral curve combined twisted-lobe Roots rotor in the embodiment of the present invention:

[0037] z a = z b = 3, n = [2, 6, 2, 6, 3, 3].

[0038] Figure 3 Schematic diagram of the profile of the high-order spiral curve combined twisted-lobe Roots rotor in the embodiment of the present invention:

[0039] z a = z b = 3, n = [2, 6, 3, 3, 3, 3].

[0040] Figure 4 Schematic diagram of the envelope line cluster of the profile of the high-order spiral curve combined twisted-lobe Roots rotor in the embodiment of the present invention:

[0041] z a = z b = 3, n = [2, 6, 3, 3, 3, 3]. DETAILED DESCRIPTION OF THE INVENTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings.

[0043] At present, the profiles of the widely used twisted-lobe Roots compressors have few design optimization parameters in terms of tooth profile serialization. To meet different requirements, it is necessary to redesign and optimize the profile parameters. In response to this, the present invention proposes a high-order spiral curve combined twisted-lobe Roots rotor.

[0044] See Figure 1 , in the high-order spiral combined twisted lobe Roots rotor of the embodiment of the present invention, the single-tooth profile A1B1C1D1E1 of the rotor profile is composed of a spiral envelope line segment A1B1, a spiral line segment B1C1, a spiral line segment C1D1, and a spiral envelope line segment D1E1 connected in sequence.

[0045] During the meshing process of the two rotors rotating in opposite directions, continuous and correct meshing can be achieved. The spiral envelope line segment A1B1 of one rotor meshes with the spiral line segment A2B2 of the other rotor, the spiral line segment B1C1 meshes with the spiral envelope line segment B2C2 of the other rotor, the spiral C1D1 meshes with the spiral envelope line segment C2D2 of the other rotor, and the spiral envelope line D1E1 meshes with the spiral D2E2 of the other rotor.

[0046] The complete rotor profile is obtained by rotating the single-tooth profile A1B1C1D1E1 around the origin of the rotor profile and then connecting the head and tail with the tooth profile A2B2C2D2E2, repeating this z times, where z represents the number of teeth of different rotor profiles; during the rotation process, the origin of the rotor profile of one rotor is O1, and the origin of the rotor profile of the other rotor is O2.

[0047] The single tooth of the rotor profile can be regarded as composed of two profile line segments A1C1 and C1E1, and these two profile line segments are respectively composed of different or the same spiral and its envelope line. Hereinafter, the combined profile composed of a spiral and its envelope line is called a spiral tooth profile.

[0048] The order of the spiral rotor profile is represented by n, generally taking an integer. The specific spiral profile equation is as follows:

[0049]

[0050] In the formula, n i represents the specific order of the spiral profile, and a and b are adjustable geometric parameters of the profile.

[0051] Derived according to the plane meshing principle, the central angle of the rotor corresponding to each spiral tooth profile satisfies the following relationship:

[0052]

[0053] Two spiral tooth profiles of different orders that satisfy this relationship form a single-tooth profile of the rotor, and different single-tooth profiles of the rotor form a complete rotor tooth profile. The specific profile matrix is as follows:

[0054]

[0055] In the formula, P i,a 、Pi,b respectively represent the parameter matrices of the spiral tooth profile curves of each section of the two meshing rotors, P a , P b respectively represent the total profile parameter matrices of the two meshing rotors. The subscripts a and b represent the two rotors respectively, and i represents each section of the spiral tooth profile.

[0056] The combined curves of spiral tooth profiles of different orders satisfy the following relational expressions:

[0057] P i,[a,b] (end) = P i+1,[a,b] (first)

[0058] P i,[a,b] (end)' = P i+1,[a,b] (first)'

[0059] In the formula, P i,[a,b] , P i,[a,b] ' respectively represent the parameter matrix of the spiral tooth profile curve of any section on the two rotors and the parameter matrix of the curve derivative. end and first represent the two points where the curve starts and ends.

[0060] The specific combination schemes of the high-order spiral combined twisted-lobe Roots rotors, compressors and expanders that satisfy the above relational expressions are as follows:

[0061]

[0062] In the formula, z represents the number of teeth of the rotor.

[0063] Rotors with different numbers of teeth z can satisfy the above relational expressions through combinations of different orders n of spiral tooth profiles.

[0064] The specific embodiments are as follows. When the number of teeth of the rotor z = 3, the following corresponding relational expressions are satisfied:

[0065]

[0066] Specifically, there are the following two schemes that satisfy the above relational expressions:

[0067]

[0068] Specifically, the spiral tooth profile orders corresponding to the central angle of the above rotor are as follows:

[0069]

[0070] Furthermore, the rotors with different numbers of teeth z have the following specific profile configuration schemes:

[0071]

[0072] Considering the design rationality and rotor applicability, only the above-mentioned order is shown In this case, the specific value can be adjusted according to the actual usage. The rotor tooth profile is combined with the corresponding number of teeth of the involute profile to obtain the complete involute-shaped twisted-lobe Roots compressor rotor profile.

[0073] In the embodiment of the present invention, the number of rotor teeth and the order of the involute of the twisted-lobe Roots compressor rotor are taken as z a = z b = 3, n = [2, 6, 2, 6, 3, 3], and the obtained symmetric rotor profile is as Figure 1 shown, and the corresponding rotor envelope clusters are as Figure 2 shown.

[0074] In the embodiment of the present invention, the number of rotor teeth and the order of the involute of the twisted-lobe Roots compressor rotor are taken as z a = z b = 3, n = [2, 6, 3, 3, 3, 3], and the obtained symmetric rotor profile is as Figure 3 shown, and the corresponding rotor envelope clusters are as Figure 4 shown.

[0075] The design method of the high-order involute combined type twisted-lobe Roots rotor of the present invention includes the following steps:

[0076] 1. Select the rotor center distance O1O2, the number of teeth z of different rotor profiles, and the adjustable geometric parameters a and b according to the volume size and pumping rate;

[0077] 2. Arrange and combine to select the order n i of the involute line segments B1C1 and C1D1, and construct the rotor profile through the selected parameters;

[0078] 3. The profile tooth profiles combined by involutes of different orders have different meshing lines and force characteristics. In the actual application process, optimize and select different arranged-profile rotors according to the sealing requirements and force performance requirements of the specific usage scenario.

[0079] The involute-shaped twisted-lobe Roots rotor profile proposed in the embodiment of the present invention is all composed of involutes and their envelopes. The present invention also provides a twisted-lobe Roots compressor and an expander. Specifically, a twisted-lobe Roots compressor has the high-order involute combined type twisted-lobe Roots rotor described above. A twisted-lobe Roots expander has the high-order involute combined type twisted-lobe Roots rotor described above.

[0080] The rotor profile of the high-order spiral combined twisted-lobe Roots rotor of the present invention has five adjustable profile parameters, including the spiral order, the number of rotor teeth, the rotor center distance, and two profile geometric parameters, providing a greater optimization space in terms of profile design and adaptability; the profile can form a series of rotor spiral tooth profiles by selecting the spiral order according to the number of rotor teeth and design requirements, and can flexibly adjust the shape of the rotor profile according to the design working conditions, so as to improve the volumetric efficiency, energy-saving performance, and dynamic characteristics of the optimized twisted-lobe Roots compressor. Compared with other conventional pump types, the compressor and expander using the high-order spiral combined twisted-lobe Roots rotor of the present invention have the advantages of fewer wearing parts, forced suction and exhaust, high pumping speed, no surging, low vibration and noise, etc.

[0081] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A high-order spiral combined twisted-lobe Roots rotor, characterized in that, Including a female rotor and a male rotor with the same profile structure, the two rotors can achieve continuous and correct meshing during the meshing process of reverse rotation, and the tooth profile of a single tooth of one rotor is composed of a spiral envelope line segment , a spiral line segment , a spiral line segment , and a spiral envelope line segment connected in sequence. The complete rotor profile is formed by the tooth profile of a single tooth rotating around the origin of its rotor profile and then connecting end to end with the tooth profile of a single tooth . Repeat this process times of rotation and connection, where represents the number of teeth of different rotor profiles; during the rotation process, the origin of the rotor profile of one rotor is , and the origin of the rotor profile of the other rotor is ; a spiral envelope line segment of one of the female rotor and the male rotor meshes with a spiral line segment of the other rotor, the spiral line segment meshes with a spiral envelope line segment of the other rotor, the spiral meshes with a spiral envelope line segment of the other rotor, and the spiral envelope line meshes with a spiral of the other rotor; Single-tooth profile Is regarded as being composed of and Two-segment profile lines. and The two-segment profile lines are respectively composed of different or the same volute and its envelope. The combined profile line segment composed of a section of volute and its envelope is a section of volute tooth profile; The equation of the spiral curve is as follows: In the formula, represents the specific order of the spiral profile, , are adjustable geometric parameters of the profile; Derivation based on the principle of planar meshing shows that the central angle of the rotor corresponding to each section of the spiral tooth profile satisfies the following relationship: Two spiral tooth profiles of different orders that satisfy this relationship form a single tooth profile.

2. The high-order spiral combined twisted lobe Roots rotor according to claim 1, wherein A complete rotor tooth profile curve is composed of different single rotor tooth profiles. The specific curve matrix is as follows: In the formula, and respectively represent the parameter matrices of the spiral tooth profile curves of each section of the two meshing rotors, and respectively represent the total profile parameter matrices of the two meshing rotors. The subscripts and respectively represent the two rotors, represents each section of the spiral tooth profile.

3. The high-order spiral combined twisted lobe Roots rotor according to claim 2, wherein, The curve obtained by combining spiral tooth profiles of different orders satisfies the following relationship: In the formula, and respectively represent the profile parameter matrix and the profile derivative parameter matrix of any section of the spiral tooth profile on the two rotors, and represent two points where the profiles are connected end to end.

4. The high-order spiral combined twisted lobe Roots rotor according to claim 3, characterized in that, Number of teeth of different rotor profiles Satisfy the following relationship: Thus, rotors with different numbers of teeth have the following orders of the involute profile of the spiral teeth with the following profile configuration schemes: In the formula, .

5. A twisted-lobe Roots compressor, characterized in that, A high-order spiral combined twisted-lobe Roots rotor as described in any one of claims 1-4.

6. A twisted-leaf Roots expander, characterized in that, A high-order spiral combined twisted-lobe Roots rotor as described in any one of claims 1-4.

7. A design method for a high-order spiral combined twisted lobe Roots rotor as described in any one of claims 1-4, characterized in that, Comprising the following steps: Select the rotor center distance based on the volume size and pumping speed , the number of teeth of different rotor profiles and the adjustable geometric parameters of the profile , ; Permutation and combination to select spiral line segments , order , and construct a rotor profile through the selected parameters; The curve tooth profiles combined by spiral curves of different orders have different meshing lines and force characteristics. In actual application, different arranged curve rotors are optimized and selected according to the sealing requirements and force performance requirements of specific usage scenarios.

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